Updated IDSA Guidelines Stress Early, Appropriate Treatment for Community-Acquired Pneumonia + Influenza

Urgent message: Just as what is predicted to be a brutal flu season picks up steam, the Infectious Diseases Society of America has released new guidelines stressing the need for timely, dual treatment in adults with community-acquired pneumonia who also test positive for influenza.

Cornelius O’Leary, Jr., MD

After more than a decade, the Infectious Diseases Society of American has published new guidelines on community-acquired-pneumonia—noteworthy for both its switch from narratives to a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) format and its fairly specific advice on the timing and mode of treatment for patients with CAP who also test positive for influenza.

The authors note that CAP is a condition with a high degree of variability, and that this recommendation does not cover the scope of prevention, diagnostic criteria, and treatment of all patients with comorbidities or who are immunocompromised. In addition, per the guidelines, antibiotic selection for the treatment of bacterial CAP involves coverage of the major players or usual suspects in CAP:

• Streptococcus pneumonia
• Staphylococcus aureus
• Mycoplasma pneumoniae
• Moraxella catarrhalis
• Haemophilus influenzae
• Legionella species
• Chlamydia pneumoniae 

This study mentions that the etiological landscape of CAP is changing due to the implementation of pneumococcal conjugate vaccine and involves several viral pathogens. Further, the authors note that adult patients with evidence of CAP who test positive for influenza should be given dual treatment with antibiotics at the time of diagnosis.

Please note that the diagnosis of CAP is outside of the scope of these guidelines.

Viral and bacterial pathogens often coexist in CAP, and there is no diagnostic test sensitive enough to differentiate between these pathogens. The authors discourage the use of serum procalcitonin as it is considered inaccurate in identifying viral pneumonia, warning providers not to use this test to determine initial need for antibiotic therapy.

Following are guideline recommendations we consider most relevant to the urgent care setting:

1. Sputum gram stain and culture are not recommended for patients being treated in the outpatient setting.
2. Blood cultures are not recommended in the outpatient setting at the time of diagnosis.
3. Routine urine antigen testing for Legionella is not recommended in adults with CAP unless there are epidemiological factors such as an outbreak or travel.
4. When influenza is circulating in the community, the committee recommends testing for influenza with a rapid influenza molecular assay (influenza nucleic acid amplification test), which is preferred over a rapid influenza diagnostic test (antigen test).
5. The committee recommends empiric antibiotic therapy should be started in adults with suspected or radiographically confirmed CAP regardless of the results of serum procalcitonin tests.
6. In addition to clinical judgement, IDSA believes physicians should use a validated clinical prediction tool for prognosis. The Pneumonia Severity Index is the preferred test to determine the need for hospitalization in adults diagnosed with CAP, not the CURB65 tool.
7. Antibiotic recommendations for initial therapy are as follows:
   • For healthy outpatient adults with no comorbidities, the committee recommends:
     1. Amoxicillin 1 g po TID
     2. Doxycycline 100 mg po BID
     3. A macrolide (Azithromycin 500 mg day 1 then 250 for 4 days (Z-pak dose) or clarithromycin) only in areas with pneumococcal resistance to macrolides <25%
   • For outpatient adults with comorbidities such as heart, lung, liver, renal disease, diabetes mellitus, alcoholism, asplenism, or malignancy:

1. 1. 1. Combination therapy: Augmentin or a cephalosporin (cefpodoxime or cefuroxime) and a macrolide (strong recommendation) or doxycycline (conditional recommendation)
         • (Be prepared for calls from the pharmacy questioning combination therapy)
      2. Monotherapy: Respiratory fluoroquinolone (levofloxacin, moxifloxacin, or gemifloxacin)

(Note: Urgent care providers are strongly advised to review the full set of guidelines, entitled Diagnosis and Treatment of Adults with Community-Acquired Pneumonia. An Official Clinical Practice Guidelines of the American Thoracic Society and Infectious Disease Society of America. It’s available online at https://www.atsjournals.org/doi/10.1164/rccm.201908-1581ST.)

Cornelius O’Leary, Jr., MD is an urgent care physician with Emergency Care Dynamics, San Diego, CA.